Similar Species The black-chinned is often confused with Anna’s and Costa’s, which are chunkier and proportionately bigger headed, shorter billed, and shorter tailed; lack the narrow inner primaries of Archilochus; and molt wings in summer. Female/immature Anna’s slightly larger; underparts more mottled, including undertail coverts (mostly whitish on black-chinned); throat often with rose-red spots; wags tail infrequently. Female/immature Costa’s slightly smaller; face often plainer; wing tips often fall beyond tail tip at rest (shorter than tip on black-chinned). Anna’s call is a smacking chip, Costa’s is a high, tinny tik, both distinct from black-chinned. See ruby-throated.